Apparatus and method for forming bump

Abstract

A preheat device ( 160 ) is provided to execute, before forming bumps ( 16 ) to electrode parts ( 15 ), a pre-formation temperature control for bonding promotion to promote bonding between the electrode parts and the bumps during bump formation. Metal particles of the electrode parts can be changed to an appropriate state before the bump formation. Phenomenally, a bonding state between the electrode parts and the bumps can be improved as compared with the conventional art. In a further arrangement of the present invention, semiconductor components with bumps can be heated under a bonding strength improvement condition by a bonding stage ( 316 ) through controlling the heating by a controller ( 317 ).

1. A bump formation method for forming bumps to electrode parts on a semiconductor substrate which is at a bump bonding temperature at which bumps are formed to electrode parts, the method comprising:
 before the bumps are formed to the electrode parts, executing a pre-formation temperature control for bonding promotion to the semiconductor substrate to improve bonding between the electrode parts and the bumps during a bump formation, the pre-formation temperature control being performed in manner so as to change a particle size of metal particles of the electrode parts of the semiconductor substrate from larger original-size particles to smaller fine-size particles, and being performed while the semiconductor substrate is in contact with a heating part for heating the semiconductor substrate, the pre-formation temperature control comprising:
 heating the semiconductor substrate to a pre-formation temperature for bonding promotion which is 30° C. to 60° C. greater than the bump bonding temperature and is not higher than a damage preventive temperature of the semiconductor substrate, 
 maintaining the semiconductor substrate at the pre-formation temperature for bonding promotion for a pre-formation length of time for bonding promotion, and 
 setting the semiconductor substrate to the bump bonding temperature after lapse of the pre-formation length of time for bonding promotion; and 
 
 after the pre-formation temperature control, forming the bumps to the electrode parts on the semiconductor substrate. 
 
   
   
     2. The bump formation method according to  claim 1 , further comprising executing, to the semiconductor substrate after the bumps are formed to the electrode parts, a post-formation temperature control for bonding promotion to promote bonding between the electrode parts after having bumps formed and the bumps, the post-formation temperature control being performed in a manner so as to promote diffusion of a material of the bumps and a material of the electrode parts at bonding interfaces between the bumps and the electrode parts. 
   
   
     3. The bump formation method according to  claim 2 , wherein the post-formation temperature control for bonding promotion comprises:
 heating the semiconductor substrate to a post-formation temperature for bonding promotion which is not lower than the bump bonding temperature and is not higher than a damage preventive temperature of the semiconductor substrate, 
 maintaining the semiconductor substrate at the post-formation temperature for bonding promotion for a post-formation length of time for bonding promotion, and 
 decreasing the temperature of the semiconductor substrate after lapse of the post-formation length of time for bonding promotion. 
 
   
   
     4. The bump formation method according to  claim 2 , wherein the pre-formation temperature control for bonding promotion and the post-formation temperature control for bonding promotion are controlled while being related to each other. 
   
   
     5. A bump formation method for forming bumps to electrode parts on a semiconductor substrate which is at a bump bonding temperature at which bumps are formed to electrode parts, the method comprising:
 forming the bumps to the electrode parts on the semiconductor substrate; and 
 after the bumps are formed to the electrode parts, executing a post-formation temperature control for bonding promotion to the semiconductor substrate to improve bonding between the electrode parts and the bumps, the post-formation temperature control being performed in a manner so as to promote diffusion of a material of the bumps and a material of the electrode parts at bonding interfaces between the bumps and the electrode parts, and being performed while the semiconductor substrate is in contact with a heating part for heating the semiconductor substrate, the post-formation temperature control comprising:
 heating the semiconductor substrate to a post-formation temperature for bonding promotion which is 30° C. to 60° C. greater than the bump bonding temperature and is not higher than a damage preventive temperature of the semiconductor substrate, 
 maintaining the semiconductor substrate at the post-formation temperature for bonding promotion for a post-formation length of time for bonding promotion, and 
 decreasing the temperature of the semiconductor substrate after lapse of the post-formation length of time for bonding promotion. 
 
 
   
   
     6. The bump formation method according to  claim 5 , wherein a pre-formation temperature control for bonding promotion and the post formation temperature control for bonding promotion are controlled while being related to each other. 
   
   
     7. The bump formation method according to  claim 1 , wherein the pre-formation temperature and the pre-formation length of time are determined based on a material of the electrode parts and gold bumps. 
   
   
     8. The bump formation method according to  claim 1 , wherein the pre-formation temperature and the pre-formation length of time are determined based on thickness of each of the electrode parts and on a diameter of a base part of each of gold bumps. 
   
   
     9. The bump formation method according to  claim 1 , wherein the pre-formation length of time is in a range of 10 minutes to 30 minutes. 
   
   
     10. The bump formation method according to  claim 1 , wherein the bump bonding temperature is 210° C. 
   
   
     11. The bump formation method according to  claim 1 , wherein each of the electrode parts has a thickness of no greater than 2500 Å. 
   
   
     12. The bump formation method according to  claim 5 , wherein the bump bonding temperature is 210° C. 
   
   
     13. The bump formation method according to  claim 5 , wherein each of the electrode parts has a thickness of no greater than 2500 Å.